With development of electronic communication industry, an electronic device, for example, a digital television (TV) or the like display apparatus has been gradually developed as an intelligent device having multiple functions such as Internet communication and information search in addition to its original functions.
For example, a display apparatus, for example, a smart TV capable of accessing Internet and receiving multimedia contents including video/audio data and packet data has been achieved to provide a personalization function by which Internet communication, information search and the like functions provided by the apparatus are personalized and managed according to users.
Such a display apparatus having the personalization function provides users, who employ this apparatus, with user accounts for personalization individually designated to them, and thus allows users to use the functions of the display apparatus. Therefore, a certain user has to be authenticated to log in to the display apparatus with his/her account.
For the user authentication, there have been generally used a face recognition method using a camera, a voice print recognition method using a microphone, a finger print recognition method using a fingerprint recognition device, a method of inputting a user authenticode such as identification (ID) and a password, and so on.
In accordance with the user authentication, the display apparatus with the personalization function allows the authenticated user to log in to a corresponding user account and thus use his/her contents previously personalized by him/her.
Such a conventional display apparatus with the personalization function may be frequently used by a plurality of users at the same time since it is shared by the plurality of users.
However, there has not been hitherto developed a display apparatus which allows a plurality of users to log in as a group and manages its functions according to groups.
Therefore, the conventional display apparatus with the personalization function cannot offer a content optimized for a group including a plurality of users to the corresponding group when it is simultaneously used by the plurality of users at the same time.
To solve this problem, a joint account may be assigned and used for the plurality of users.
However, in this case, users who employ the display apparatus with the personalization function are often changed, and it is thus impossible to provide contents optimized for a group of changed users to the corresponding group whenever users are changed.
Also, in case that the conventional display apparatus with the personalization function employs the face or voice print recognition method for the user authentication, which has a poor recognition rate, it is impossible to log in for users to the user account or the joint account due to a recognition error, even though the users have already been registered thereto.
Also, the conventional display apparatus with the personalization function by itself can not subscribe to an information providing server such as a social network service (SNS) server providing a SNS and create a user account thereof. Accordingly, users of, for example, mobile devices such as hand phones can not make an information sharing relation such as a friend or the like with the conventional display apparatus to shares various pieces of information or various functions therewith based on the information sharing relation through the SNS of the information providing server.